Yes, what do you do when you suddenly find yourself transformed into a quadruped and can no longer use a toilet designed for a biped? I’m being somewhat half-serious here…but it does seem to call for a practical solution. What would housing (stables, maybe?) be like for centaurs?

I don’t see that they necessarily need to be anything like what humans use. Except, male centaurs could have latrines. But toilets would have to be an altogether different creation because centaurs don’t need to squat or sit to do their major business. Maybe the room devoted to elimination and such would be separate from centaur housing. Of course, this all stems on the idea that there is a modern centaur society rather than a primitive hunter/gatherer community.

We used to call those “outhouses” in the old country. 🙂 And yes, I’m thinking of a modern centaur civilization. Probably the easiest solution (for both stallions and mares) would be to have a strong, reinforced “grate” in the outhouse. The centaur goes in, stands over the grate, and does his/her business. You might want to have some kind of flushing mechanism that delivers the waste to a septic tank/field.